Process of distilling glycerin.



F. J. WOOD.

PROCESS OF DISTILLING GLYCBRIN. APPLICATION FILED JAN. 16, 1910.

L,{)89,.383 Patented Mar. 3, 19M

Hoiwafer Sfealn/ 8M ue/wto z fun/V J Wood the city of New skilled in the art to which it FRANK J'. 'WOUD, OF ITE'W' YORK, ill.

PROCESES 01E ICFISTEIJ" LING- Gilli?!) To all whom it may concern Be it lcnovm that l, Fnaian. l. l i oon, of York, State oi New York, have invented certain new a: l useful lni proven'ients in Processes of Distillii (ly crin; and I do hereby declare the fell. to be a full, clear, and exact dcscriptioL o the invention, such as will enable others appcrtains to The two main nu-noses of the present inl l i vention are to prevent the accumulation in the stills of refuse or roots, and to minimize the foaming which apt to occur d uring distillation owing to the presence of water in the glycerin supply. To attain these purposes I first eliminate the water by vaporizing it out of the glycerin and intro duce the substantially anhydrous ;lycerin to the first still of a plurality of stills connected in series and to each of the stills in succession, or to as many as desired, a low level or? the glycerin being maintained in each of the stills. A portion of the glycerin current is distilled at each still and condensed, and the ioots are finally collected and treated, chemically or otherwise. The single steam column used in all of the distillations also passes to all of the stills in succession, as in the Letters Patent above referred to.

In the accompanying drawing I have'illustrated an arrangement of mechanism appropriate to carrying out the present process.

As illustrated, a plurality of stills in series;

is shown at l, 2, 3, l, and their respective hot water glycerin condensers at 5, (i, Y, 8, each still being connected to its condenser by a pipe 9, while a pipe 10 leads the steam, out of which the glycerin vapors have been condensed, to the succeeding still. The condenser 8 is shown in communication with. a cold water sweet-Water condenser 12 from which a pipe 13 leads to a vacuum pump 14, and from which a'pipe 13 may lead to an evaporator, not shown.

Each of the stills is provided with a connous glycerin heater i5, supplied with ll steanrironipipe to, "l oueh which heater 7 1H withdrawn from the bottom of the still may be forced by pump 17 and again introduced f still at the upper part and :lallingg; in divi ed columns be l with the gllP. arrangement of still and heater and the interior construction of the still are, or may be, lilci those shown in. Letters Patent No. 910,440 issued on n'iy application January 9, i903. The pumps 17, preferably of the rrngal i'zypc, in v, as operated by a shaft 13) driven by a hand 20 connected with a suitable engine. The pipe loading from the heater of still 1 into the upper part c still is conneited to the succeeding hya pipe having a valve 23 there- 1, the pipe entering the still near the ottcin 'lhercot. This (llrlSlOn of the heated l'lvccrin by which a portion goes into still nd the rest into still 2 may be repeated \vi h as many stills as desired.

n practice the normal level of within each still is about that still 1, thi vOlUTHC by the pump l7 the glycerin indicated in being readily maintained and shown by a sight open mg indicated a t in still 2. The space thus ntaincd between the outlet of pipe 21 within the still and the body of glycerin at the bottom or the still aitords ample opportunity for the graritating streams of glycerin to associate with the steam column entering at 153 and to vaporize and pass upward through. pipe 9 to the condenser without being retarded by an undue quantity of liquid glycerin in the stills. Furthermore by maintaining the relatively low level of glycerin in the stills the tendency of impurities to prime over withthc vapors and spoil the condensate is reduced to a mininnun.

At 524- l. have shown the pro-heater to which glycerin may be supplied through a. pipe 25 and from which it passes to still 1 through a pipe 26 having a valve 27. High pressure steam passes through a coil 28 contained in the preheater. The water that may be contained in, or carried by, the glyc erin will vaporize at temperatures from 110 to 18 degrees Fahrenheit, under the vacuum maintained in the pits-heater and stills, while the body of glycerin would require 280 degrees Fahrenaeit or more. Hence by the steam within the coil being at a temperature less than the boiling point of the glycerin the substantially liquid condition of the latter will not be materially altered but the water will be converted into steam and will 'pass through pipe 29 to the sweetwater condenser 12, carrying with it such glycerin and volatile impurities as may have evaporated in the pre -heater. This leaves a substantially anhydrous glycerin to be supplied to still 1 on opening the valve 27. The pump 17 being in Operation withdraws the glycerin from' the still and forces it through the heater and pipe 21 to the still. In passing through pipe 21, however, the glycerin finds an outlet through pipe 22 and (the valve 23 being open) thence to the still 2,

the pipe being on a plane lower than the outlet of pipe 21. The portion of the glycerin continuing through pipe 21 past pipe 22 to the still gravitates therein in divided columns and unites with the steam current entering at 18 and the combined vapors pass through pipe 9 to the hot water condenser 5 where the glycerin is condensed out of the steam and the latter passes through pipe 10 v to still 2 according to the multiple effect principle set forth in the Letters Patent No. 881,525 above referred to. The unvaporized glycerin and foots will fall to the bottom of the still to be again withdrawn by the pump and heated and returned to the one or conducted to the other of the stills. Some slight quantity of water may remain in the glycerin when it leaves the pre-heater, but in the first still this will readily vaporize and will not be sufficient to cause foaming.

The glycerin from the pre-heater 24: might supply any number of stills connected as by pipes 22 and the current of steam would be available for all the distillations. Naturally, however, the steam when pure is of greater value for attaining a pure distillate than when it carries with it the vapors of impurities and fatty acids which might ,con-

e taminate the glycerin. For this reason when the single steam current is being supplied to a plurality of stills in succession, the stills may be livided into two or more groups, the first group distilling first quality and the subsequent groups distilling the quality that is to be distilled again. Inthe present case, for instance, I prefer to use once-distilled glycerin in the group comprising stills l and 2 and to inject pure steam through pipe 18; pass the glycerin from still 1 to 2 as stated, but close valve 30 between stills 2 and 3. The steam current, however, is maintained and may continue from condenser 6 to the second group ofstills, 3 and 4. Here crude glycerin may be distilled as the partially refined glycerin was distilled in stills 1 and 2. I have accordingly shown at- 31 a crude glycerin pre-hcatcr forming part of the connection between a receptacle 32 and still 3', the pre-healrr ontaining a steam coil 33. .The operation in this pre-heater, stills 3 and 1 and their respective condensers is the same as described with reference to the pre-heatcr 24c and stills '1 and 2. From the last glycerin condenser 8 the vapors pass to the steam condenser 12 and then through pipelil to an evaporator, where may be re covered the glycerin carried o er from condenser S and that which may have vaporized in the pro-heater and passed through pipe 29. The unvaporized glycerin and the foots in still 4 pass to a monte jus 3a in communication with the vacuum pump. By steam pressure en ering the monte jus as at 35 the foots as wel as the unvaporized glycerin are forced out of the system into a receptacle indicated at 36, the contents of which may be treated by any appropriate method to recover the glycerin.

The step in the process of utilizing a second pre-heater as 31 is obviously no departure from the idea present in the pre vious step it is recited merely as showing an appropiiate use of the steam current after it has served in two or more distillations of relatively pure glycerin and also a manner of disposing of the foots contained vin the once distilled glycerin.

I claim as my invention 1. The process of efiecting a series of distillations of glycerin or similar material, consisting of conducting a body of glycerin successively to a plurality of stills and condensers in series and vaporizing and condensing a portion of the glycerin at each still and condenser, respectively.

2. The process of effecting a series of distillations of glycerin or similar material,

consisting of vaporizing the water out of the glycerin, conducting the substantially anhydrous glycerin successively to a plurality of stills and condensers in series, and Y vaporizing and condensing a portion of the glycerin at each still and condenser, respectively. v

3. The process of efi'ecting a series of distillations of glycerin or similar material, consisting of vaporizing the water out of the glycerin, conducting the substantially anhydrous glycerin to the first still and condenser of a series of stills and condensers, vaporizing and condensing a portion of the glycerin contained within the first still and a condenser, transferring the balance of the glycerin from still t6 still in succession, and

vaporizing and condensing at each still and condenser respectively.

' 4. The process of effecting a series of distillations of glycerin or similar material, consisting of conducting a body of glycerin successively to a plurality of stills in series, and vaporizing a portion of the glycerin at each still and condensing in condensers which alternate with each still by the agency of'a single current of steam conducted successively to all of the series of stills altervious distillation have been condensed in nating with condensers. one of said condensers.

5. The process of effecting a series of dis- In testimony whereof, I have signed this tillations of glycerin or similar material, specification in the presence of two sub 5 consisting of conducting a lofody of glycerig scribing witnesses.

successively to a plurality o stills arrange 1 I in alternate series with their respective c0n LRANK WOOD densers, and combining with the glycerin Witnesses: at each of the succeeding stills the steam GRAFTON L. MCGILL, 10 out of which the glycerin vapors of a pre- D. H. BATES, Jr. 

